Brandy butter should just be butter, sugar and brandy, though if you’re buying ready-made, do check the ingredients because as we know, manufacturers do tend to add flour to the oddest things. Brandy, incidentally, is gluten free (unless something is added post distillation). I always make ours, and I do it by eye (and taste), not by measure, so here are a couple of proper recipes for you. Interestingly, both use brown sugar where I use icing sugar (confectioners’ sugar) so I might try it with brown sugar this year:

Custard may be more risky. Traditionally, this is made using cornflour (see Mary Berry’s recipe for custard), and it is surprisingly easy to do, though I confess that when I make custard I omit the cream… If you’re buying custard, do check just in case. If you’re in the UK, then you can rely on Ambrosia and Bird’s.

Another option is to use a good thick yoghurt, probably Greek. And Greek yoghurt is available at 0% fat, if you’re trying to monitor such things over Christmas…